Friday, September 28, 2012

9/13: Rick and
Pat Schwai visited Hawk Ridge and were treated to both a glorious day and the
second largest count number so far (6600+) this month. Pat noted, “I
didn't expect the hawks to be flying so high that they were invisible to the
naked eye and still tiny with my 8x32 binoculars.”

9/16: Jim Ferguson went out on Lake Tomahawk for a last day of
summer pontooning and was surprised to come across two red-necked grebes. He
observed, “The two birds stayed close together all the time. We also
counted 39 loons. All the birds were on the western end of Tomahawk Lake.”

9/17 Sharon
Lintereur in Lake Tomahawk watched a barred owl hunting in her woods and was
able to get some fine pictures (see photo).

9/19: Ellen and Kit Deubler had a rare visitor, a bull moose, at
their home on Elsie Lake in the Township of Lac du Flambeau (see photo).

9/23: Mary, Callie, and I were very lucky to come across three
migrating Lapland longspurs on one of the dikes in Powell Marsh.

Bumper Crop of Acorns

Our
native red oaks have outdone themselves this fall in their production of
acorns. There are so many underfoot in places it’s hard to walk! Productive red
oak trees can produce over 1,000 acorns in a banner year – some white oaks are
known produce over 10,000 acorns with yields reaching as high as 6,000 pounds
per acre. However, white oaks are quite uncommon in the Northwoods, attaining
their northern range boundary usually a few counties south of us.

I’m sure a host of wildlife species
have also taken note of the acorn bounty. Among birds, ruffed grouse, wild
turkey, red-headed woodpeckers, blue jays, crows, white-breasted nuthatches ,
brown thrashers, rufous-sided towhees, and common grackles are heavy consumers
of acorns. And though red oak acorns are more bitter due to their high tannic
acid content than white oak acorns, many mammals consume them, chief among them
being rodents and squirrels, as well as black bears and white-tailed deer. For
deer, acorns are preferred above all other food items whenever and wherever
they are available.

But wildlife are not the only
consumers of acorns; people have consumed acorns for thousands of years. In
fact, acorns are still a commercial food crop in China and Korea, and are
harvested to a lesser degree in Mexico and Japan. You can buy acorn flour
online right now from www.acornflour.org. Acorns
were particularly important to certain tribes in California, comprising half of
their diet! There, oaks were planted, transplanted, and intensively managed in
“orchard-like” settings.

But what about Native American use
of acorns in northern Wisconsin? The Woodland tribes of the Upper Great Lakes
Region relied on seasonally abundant plant and animal resources, chief among
them in the autumn being fall-spawning fish and wild rice. But archaeological
evidence indicates that acorn use was also widespread, though the sweeter
acorns (white and bur oak) were preferred over red oaks. Red oak acorns require
leaching of their tannic acid to be edible, but the practice was common, as
described in the Menominees by Huron Smith in 1923: “The acorn was boiled till
almost cooked. The water was then thrown away. Then to water, two cups of wood
ash were added. The acorns were put into a net and were pulled out of the water
after boiling in this. The third time, they were simmered to clear them of lye
water.” Smith added, “Because the red oak was so abundant in Ojibwe territory,
the acorns were one of their most important starchy foods.”

Environmental
Analysis of the Rest Lake Dam

On
9/15, the WDNR released an Environmental Analysis (EA) related to the eventual
new operating order it will issue on the Rest Lake Dam. The purpose of
the EA is to provide a factual disclosure of the levels and flows of the river
and how the large community of species are impacted, the management
alternatives considered, and their anticipated environmental impacts. Here is a
beginning attempt at summarizing this complex document:

Summary
of the Issue

The
Rest Lake Dam, located on the Manitowish River in Manitowish Waters and
incorporated into the County ‘W’ bridge, creates an upstream reservoir that
controls the water level on a chain of ten natural lakes and river channels
known as the Manitowish Chain of Lakes. Elevations upstream of the dam are
raised between 9.2 and 13.5 feet.

Downstream
of the dam, the Manitowish River flows through three small lakes and then
travels another 15 miles until the Manitowish and Bear Rivers combine to form
the North Fork of the Flambeau River, eventually flowing into the
Turtle-Flambeau Flowage.

The
chain of lakes is drawn down about 3.5 feet every fall to protect piers and
boat houses on the Chain. The drawdown results in significant autumn flooding
downstream. The Chain is then refilled every spring after most of the ice is
off Rest Lake, which unfortunately is after nearly all of the snowmelt has
already gone downstream. Based on USGS estimates, to raise or lower the Chain 1
inch takes 14.8 million cubic feet of water. This amount of water translates to
a daily flow of 171 cubic feet per second that is either taken from, or added
to river flows downstream of the dam. The natural streamflow below the dam is
thus profoundly altered in order to empty or fill the Chain – photographs
throughout the EA dramatically illustrate this.

The
current owner of the Rest Lake Dam is Xcel Energy. The hydropower generated
downstream resulting from the fall drawdown of the Chain was evaluated by the
Federal Energy Regulatory Commission, which in 2001 concluded that the
management of water levels and flows was “neither used and useful nor necessary
or appropriate to maintain or operate” hydropower generation.

Thus,
given that the dam has no functional value to Xcel, its current operation is
summarized by the EA as “focused primarily on upstream water interests
including minimizing possible ice damage to piers and shoreline structures, as
well as keeping water levels above the dam in a narrow operating range near the
maximum water level from June through October.”

According
to the EA, the problem with this management strategy is that at any time of
year, the minimum river flow required at a dam stems from Chapter 31.34
Wisconsin Statutes, which states that a dam must, at the minimum, discharge at
least 25% of the stream’s natural low flow. This is calculated by estimating
the “Q7-10 flow” which is
defined as the lowest average flow for a consecutive seven-day period with an
average recurrence interval of ten years. The Q7-10 is mainly used for the permitting of
wastewater discharges, and, importantly, these flows are not considered
protective of aquatic life and habitat. The USGS has since estimated the Q7-10
for the Manitowish River to be 40 cubic feet per second (cfs).

The
downstream flows of the Manitowish, however, have often been lower than 40 cfs,
sometimes for months at a time, and thus of very significant ecological concern. So, the DNR began meetings
in 2002 to re-evaluate the 1937 operating order that today still acts as the
legal directive for the management of the dam.

The
other statutory issue surrounding the management of the Rest Lake Dam stems
from Wisconsin’s
Public Trust Doctrine (Wisconsin
Constitution: Article IX, Section 1), which establishes public water rights and
the State’s obligation to protect those rights in navigable bodies of water.
The Wisconsin Supreme Court has declared that the State holds navigable waters
in trust for all citizens, and that public water rights such as water quality,
quantity, scenic beauty, and recreational use need to be protected for the
benefit of current and future generations.

In
response to these statutory directives, intensive data-collecting studies were
eventually undertaken by the DNR, and in November of 2009, the USGS placed gaging
stations to record the river flow on the three largest inflows to the Chain
(the Manitowish River, Rice Creek, and Trout River), the water level elevation
at the dam, and the river flows downstream of the dam. This information, along
with historical dam operating records and nearby long term gaging stations on
the Bear and Trout Rivers were used by USGS to develop inflow models for the
Manitowish River at the Rest Lake Dam.

Other
information gathered in the EA addressed the major sources of water loss from
the Chain and the rivers, which include water withdrawals for cranberry
operations, private irrigation, evaporation, and plant transpiration. It also
evaluated other issues such as water quality, aquatic habitat with discussion
of the functions and values of wetlands, fisheries populations and habitats,
wildlife populations including birds, mammals, amphibians and reptiles, and
mussels, wild rice habitat, and cultural values such as local economics, land
values, recreational uses, and shoreline structures.

Cranberry
Growers Water Withdrawals

The
entire EA is thorough, essential reading and quite revealing. For instance, the
EA quantifies what the actual water withdrawals are from the three cranberry
operations around the Manitowish and Trout Rivers.

Cranberry
production uses water to irrigate cranberries during the growing season, to
flood beds for harvest in August, to flood beds in winter to protect the vines
from freezing/drying, and to either flood beds or irrigate to protect the
plants from frost in the spring.

Approximately
960 acres of cranberry production is located downstream of Wild Rice Lake where
pumps keep water levels high on Little Trout Lake, from which water is then
pumped or flowed to individual cranberry beds. Water diverted to these
cranberry beds is likely not returned to the Manitowish Chain because it is
located in the Bear River sub-watershed.

The
pumping station is only operated when water levels on Little Trout Lake are low
during dry years. In 2007, a drought year, operating records indicate that
pumping occurred 24 hours a day from June to October. Given the 10-14 cfs
pumping rate from this operation, the USGS estimated the amount of water
withdrawn from the Chain and diverted to Little Trout Lake ranged from 11 to
27% of the natural inflow of the river.

Another
cranberry pumping station located upstream of Wild Rice Lake is used to keep
water levels high on Great and Little Corn Lakes. Approximately 177 acres of
cranberry production occurs
in this location. This cranberry operation diverts from 2 to 100 percent of the
flow of the Trout River when the pumps are turned on. For example, on December
11, 2009, USGS measured 2.41 cfs below the pumps and 25.0 cfs upstream (a
diversion of 22 cfs). This means that under low flow conditions, the pumping
rates can and were measured by the USGS gage to temporarily reverse the
direction of flow on the Trout River.

The
third cranberry pumping location has approximately 41 acres of cranberry beds
and takes water out of Alder Lake, recycling it directly back to where it was
withdrawn minus losses due to evaporation and evapotranspiration.

A
fourth operation is currently under construction in the watershed that will
have approximately 20 acres of cranberry beds, and which will divert water from
Lower Gresham Lake. The outlet of this lake is Gresham Creek, which is a
tributary to the Trout River upstream of Wild Rice Lake.

Comments
on the draft EA need to be received by the DNR by 10/31/12. An updated Rest
Lake Dam operating order will be drafted after the certification of the EA.

I
highly recommend reading the EA. It’s a lesson in the complexity of natural
systems and our relationships to them. My hope is that objective and bighearted
discussion will follow, the sustainable management of the rivers and the Chain
will ensue, and people will come together to work with the DNR to optimize the
health and integrity of the rivers and lakes throughout this watershed.

Friday, September 14, 2012

We still had
female and juvenile ruby-throated hummingbirds coming to our feeders as of
Saturday morning, 9/8, but given the strong northwest winds over the weekend, I
suspect most of our local nesting hummers have now hit the migratorial road. Males
precede the females in spring and fall migration, with the juveniles of both
sexes lagging somewhat behind the adult females in the fall. The male’s
earlier departure in the spring gives them time to establish territories so
they can successfully court arriving females at the beginning of the breeding
season, and they follow the same pattern for fall migration in order to
establish their winter territories. If you have hummingbird feeders, you know
how extraordinarily territorial the males can be during the breeding season, an
obsession they apparently continue with throughout the winter.

Ruby-throated
hummers winter throughout Central America, with a few stopping short to winter along
the western Gulf Coast. Many fly across the Gulf of Mexico, but many also follow
the coastal route around the Gulf. Large numbers are often observed flying low
over wave tops to make landfall during spring migration; however, I’m unable to
find any information as to whether they fly this low during fall migration.

On average,
adult ruby-throated hummingbirds have a mass of only 1/10th of an
ounce (3.5 grams.) Despite their almost indiscernible weight, many of these
birds fly nonstop across the Gulf of Mexico during fall and spring migration, a
one-way trip of more than 500 miles. To reach the
Gulf, the hummers migrate by day, but to cross the Gulf, they typically leave at dusk and fly for 18-22 hours to
reach landfall.

To accomplish
this flight, individuals will double their body mass to 6 grams by fattening on
nectar and insects prior to departure. When they
reach landfall, however, they typically weigh only 2.5 grams, having lost more
than their entire normal body weight. While this may sound like a lot to us,
losing only a tenth of an ounce while flying 500 miles non-stop is pretty
amazing fuel efficiency – Prius owners take note!

Given their
near weightlessness, it only makes sense that wind direction and velocity would
strongly influence their migration. One study conducted along the ridges at
Hawk Mountain Sanctuary, Kempton, PA, found that migrants were most numerous
after the passage of strong cold fronts and northwest winds.

The
ruby-throats’ overland fall migration occurs nearly synchronously with the peak
flowering of jewelweed (also known as spotted touch-me-not or Impatiens
biflora), an important nectar source, suggesting that jewelweed may influence
the timing of migration.

For a hummer
that just hatched, there's no memory of past migrations, only an instinctive urge
to put on a lot of weight and fly in a particular direction for a certain
amount of time, then look for a good place to spend the winter. Once it learns
a route, the hummer will likely retrace it every year as long as it lives.

The initial migratorial
urge is triggered by the shortening length of daylight as autumn approaches,
and has nothing to do with temperature or the availability of food; in fact,
hummingbirds migrate south at the time of greatest food abundance. When the
bird has put on enough fat, it migrates.

Although
hummingbirds may fly over water in company of mixed flocks of other bird
species, they do not fly in flocks with other hummers. Individual birds may
spend the winter anywhere in Central America where the habitat is favorable (most ruby-throats only migrate as far as Panama), and most very likely return to the same location each winter, though
banding data is limited.

To go from Wisconsin
down to the Gulf coast would take a hummer about 4 or 5 days, assuming the
hummer did not spend more than one day resting at any one place. It would then
take a day to cross the Gulf, and another couple of days to reach its
destination in Central America. But with big rest stops to wait for good
weather and to build back up fat reserves, it probably takes about two weeks
for “our” hummers to reach their winter homes. One study
found that they usually arrive in Costa Rica by late September to early October.

Some amazing
hummer factoids:

They beat
their wings about 60-80 times per second in normal
flight.

Their
hearts beat about 250 times per minute while at rest, and about 1,220 per
minute while flying. Their hearts are about 2.5% of their total body weight.

Autumn equinox
is right around the corner, occurring this year on 9/22 at 9:49 a.m. CST. The word "equinox" derives from Latin term "æquinoctium"
which, in turn, came from "æquus" (equal), and "nox"
(night).It, of course, refers
to the moment that occurs twice a year when the nighttime is equal to the
daytime.

The seasons of
the year are caused by the 23.5º tilt of the earth's axis. We Northern
Hemisphere inhabitants are slanted furthest away from the sun during winter
solstice, and slanted most toward the sun during summer solstice.

Autumn equinox
is noteworthy because it marks our transition into days that have more darkness
than daylight. Combined with killing frosts, the departure of most of our
birds, and the rattle of brittle leaves in strong autumn winds, it can be a
difficult emotional adjustment. But it’s also the time of many harvests,
brilliant leaf-changing colors, and a crispness in the air that makes you just want
to walk and explore as much of this world as you can. As always, the perception
of outer landscapes depends wholly on one’s
inner landscape. Bringing an energetic, joyful countenance to a morning makes
all the difference.

Hawk Ridge in Duluth

Hawk
migration is now hitting its peak. What makes a good migration day at Hawk Ridge?Birds and the weather are both
unpredictable (note this disclaimer!!), but northwest or west winds are best,
and the more days in a row, the better. North and southwest winds are
okay. South, southeast, and east winds are not good. The day before,
or a couple of days after a strong front, usually produces more birds, and the
flight essentially shuts down in the rain and fog.

So, while on average this weekend
usually produces the biggest flights of the year, Mother Nature always bats
last. Keep an eye on the weather forecast for Duluth, and head for the ridge
when peak conditions appear to maximize your chances for a truly big day. And
by “big,” I mean BIG – the record day at Duluth was on 9/15/2003 when over
102,000 hawks flew over the ridge. They already had a pretty big day this year on
9/9 when 16,135 hawks were counted, so the flight is on!

New moon occurs on 9/15. On 9/18, look at dusk for Saturn 5
degrees north of the crescent moon. On 9/19, look for Mars almost on top of the
crescent moon.

Armageddon

As
of 9/10, we’ve yet to experience our first frost, an event so destructive that
author Diane Kappel-Smith writes: “Winter is a
predictable kind of Armageddon, a calamity calmly weathered, an end of a world
that they [wildlife] understand and are preparing for . . .”

The
first frost marks the end of the growing season for hundreds of species of
plants and the end of life for literally millions of insects. While gardeners
and farmers pay attention to it, for wildlife, there may not be a more
important event than this in the entire natural year.